# BSI C5 CRY-02 — Encryption of data for transmission (transport encryption)

- Source: https://support.icompaas.com/support/solutions/articles/a_gen_bsic5_cry02_c720a99d2f-bsi-c5-cry-02-encryption-of-data-for-transmission-transport-encryption
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [BSI C5 (German Cloud)](https://support.icompaas.com/support/solutions/c_gen_bsi_c5) › [Cryptography & Key Management](https://support.icompaas.com/support/solutions/folders/f_gen_cgenbsic5_cryptographykeymanagement)
- Last updated: 2026-05-30
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

BSI C5 · Control CRY-02 · Priority: critical · Component: Cryptography & Key Management

### What this control covers

Implements strong encryption and authentication for data transmission over public networks, ensuring confidentiality and integrity. Uses state-of-the-art protocols to protect cloud customer data from interception or manipulation during transit.

### Why it matters

A defended network limits blast radius after an initial compromise — the difference between an incident and a breach is often the controls described here.

### How to implement

#### AWS

Segment workloads into separate **VPCs/accounts per environment**. Use **security groups** as stateful allow-lists (least-port, source by SG ID not 0.0.0.0/0) and **VPC Flow Logs** to CloudWatch/S3. Front public services with **AWS WAF + Shield Advanced** and use **PrivateLink/VPC Endpoints** to keep service traffic off the internet.

#### Azure

Use **Network Security Groups** and **Application Security Groups** for east-west, and an **Azure Firewall** or NVA in a hub VNet for north-south. Enforce **Private Endpoints** for PaaS and turn on **Defender for Cloud — Network** for adaptive hardening recommendations.

#### GCP

Use **VPC Service Controls** to draw a perimeter around sensitive APIs and a hierarchical **Firewall policy** at the org/folder level so projects inherit a deny-by-default posture. Front HTTP workloads with the global **Cloud Load Balancer + Cloud Armor**.

#### Google Workspace

Enable **client-side encryption** for Drive/Docs and turn on **Drive Labels + DLP** rules to prevent external sharing of regulated data classes.

### Evidence to collect

-   `infra_scan` — See the iCompaas Evidence library for the canonical source for this evidence type.

Infrastructure posture tooling (AWS Config, Azure Policy, Nessus) verifies platform hardening. Focus: Encryption of data for transmission (transport encryption).

### Quick checklist

-   Security — Protection / - Configuration
-   Confidentiality — Protection / - Configuration
-   Protection — Protection / - Configuration
-   Data — Protection / - Configuration
-   Authentication — Protection / - Configuration
-   Encryption — Protection / - Configuration

### Related articles on this site

-   [Ensure Kafka Cluster Encryption at Rest Uses Customer Managed Keys (CMK)](https://support.icompaas.com/support/solutions/articles/62000233567-ensure-kafka-cluster-encryption-at-rest-uses-customer-managed-keys-cmk-)
-   [Microsoft Cloud Security Posture Management (CSPM)](https://support.icompaas.com/support/solutions/articles/62000234105-microsoft-cloud-security-posture-management-cspm-)
-   [Enable Transparent Data Encryption with Customer-Managed Keys on Azure SQL Servers for Enhanced Data Security](https://support.icompaas.com/support/solutions/articles/62000234802-enable-transparent-data-encryption-with-customer-managed-keys-on-azure-sql-servers-for-enhanced-data-)
-   [Enable Transparent Data Encryption (TDE) on Azure SQL Databases to Protect Data at Rest](https://support.icompaas.com/support/solutions/articles/62000234805-enable-transparent-data-encryption-tde-on-azure-sql-databases-to-protect-data-at-rest)

## Related compliance guidance

- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them.
- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.